JPH0548701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a knee joint in a skeletal prosthesis that combines a uniaxial joint mechanism and a cross-legged mechanism.

<Prior art> In general, the knee joint of a skeletal prosthetic leg that is fitted with an exterior member that is a urethane cover that has the same shape and color as a normal limb is simply a brake drum type knee drum installed at the upper end of the lower part of the joint. , connecting the upper part of the joint to the front end of the knee drum to form a joint structure;
In addition, an elastic band for knee extension is stretched across the front surface of the upper part of the joint and the front surface of the lower leg skeleton connected to the lower part of the joint. In this case, conventionally, this type of knee joint mechanism was aimed only at flexion during walking, and was used in movements associated with sitting on a chair, sitting down on the floor or tatami mats, and crossing one's legs or sitting cross-legged. I was unable to do the so-called cross-legged swing, which involves rotating my legs laterally.

<Problem to be solved by the invention> For this reason, in recent years, knee joints have been
It has been improved so that it can not only bend forward and backward while walking, but also rotate laterally (cross-legged). In this case, the rotation mechanism includes a push button that protrudes horizontally from the outer shell member on the socket side that is connected to the upper part of the joint.
The click mechanism is used horizontally to press a locking pin facing the core shaft of the upper part of the joint that fits into the outer shell member attached to the rear end of the push button, and the push button is pressed from the outside across the urethane cover each time. A pressing operation is performed to release the double engagement between the outer shell member for the socket and the upper part of the joint, and to swing the lower leg side below the upper part of the joint laterally. That is, in the conventional cross-legged swinging mechanism, each pushbutton operation is performed manually from the outside, making it cumbersome to handle.

Furthermore, since the extension mechanism for returning the knee from bending during walking involves elastic bands disposed on the outer surfaces of the upper and lower parts of the joint, it has the defect of digging into the urethane cover. In addition, the inside of this urethane cover had to be slightly cut away in areas corresponding to the elastic band and the push button, which was troublesome to manufacture.

In view of the above-mentioned circumstances, the present invention solves the above-mentioned problems by using an extension lever that is inserted into the prosthetic leg body to restore the knee flexion, and by using a cam that automatically disengages the upper part of the joint when the knee bends beyond a predetermined angle. The purpose of this invention is to provide a knee joint in a skeletal prosthesis that solves the above problems.

<Means for Solving the Problems> The present invention includes a knee drum having a rear end provided with an extension lever controlled by an elastic mechanism in the lower part of the joint, which is pivotally attached to the upper end of the lower part of the joint by a drum shaft. A support arm for the upper part of the joint is attached to the front part of the knee drum, and a rotary plate for cross-legged sitting is rotatably placed on the upper surface of the upper joint, and the pin engagement between the rotary plate and the upper part of the joint is controlled by the drum. Due to the angle adjustable fixed cam installed on the shaft,
It is designed to come off when the knee is bent over a predetermined angle.

<Function> Due to the above-mentioned configuration, during normal walking, this knee joint is lowered forward by a predetermined angle when transitioning from the kick-off position to the swing phase, and at the end of the swing phase, the knee joint is moved downward by the extension lever at the end of the swing phase. Forced push back to extend and walk smoothly. In addition, if the knee is bent deeper than the maximum knee flexion during a prescribed walk, such as when sitting down, the pin-shaped follower that hangs down from the top of the joint will touch the cam surface of the fixed cam at the end of the drum shaft at the bottom of the joint. The driven body moves back the click shaft that engages the pin between the upper part of the joint and the rotary plate, and the rotary plate side becomes freely rotatable in the lateral direction. This means that the lower leg side, which is the lower part of the joint, will swing laterally if the socket-side rotating plate is used as a reference. That is, if the knee is bent at a predetermined angle or more, the click axis will automatically come off and the so-called cross-legged swing will be possible.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

Reference numeral 1 denotes a lower part of the joint that connects the lower leg pipe 2 to the lower part of the joint, and a knee drum 4 in which a brake slit 3 inclined upward in the front part is formed in the support piece part 1a protruding from both sides of the rear upper end of the lower part of the joint 1. drum part 4a
is supported through a fixed drum shaft 5, and a support arm 6a protruding from the lower front end of the upper joint 6 is fitted into the fitting part 4b provided at the front end of the knee drum 4,
A knee joint main body 8 is constructed by connecting through the support shaft 7, and a horizontal socket-side cross-legged rotary plate 10 is installed on the upper surface of this joint upper part 6, and a center of the implant is installed in the center of this joint upper part 6. The shaft 9 is inserted into the central hole 10a of the rotating plate 10, and a locking pin 11 with a spring 11a disposed inside the rotating plate 10, which protrudes downward from the periphery of the rotating plate 10, is normally connected to the joint (when not swinging horizontally). A click mechanism is provided on the pin-type driven body 12 installed at the peripheral edge of the upper part 6, and this driven body 12 is a fixed cam whose angle is adjusted by a tightening shaft part 32 provided at the side end of the drum shaft 5. It can be moved up and down according to the displacement of the cam surface 13a of 13, and constitutes a cross-legged swinging mechanism 14. Further, a bendable extension lever 16 is connected to a lever receiving branch 15 integrally provided at the rear end of the knee drum 4, and the lower end of the extension lever 16 is connected to a support provided protruding from the inner lower end of the joint lower part 1. It is connected to a sliding piece 19 with a spring 18 which is attached to a tube 17 and serves as a spring mechanism, and the entire knee joint 20 is of a safe walking type.
In this case, the lever part 6b installed on the lower center surface of the joint upper part 6 is brought into contact with the tightening piece part 4c which is the upper part of the slit of the knee drum 4. Further, the rotating plate 1
An alignment adjustment means 22 is installed on the top of 0. This alignment adjustment means 22 is a rotary plate 1
The curved surface 21a of the bowl-shaped ring 21 placed on the upper surface of 0
The curved surface 23a of the lower surface of the annular socket pedestal 23 is overlapped with the curved surface 23a of the lower surface of the annular socket pedestal 23, and the taper piece body 24 installed in the ring frame 23b of the socket pedestal 23 is aligned by the retraction amount of the four regulating bolts 25 inserted laterally from the outer periphery on all sides. It is structured to determine the The tapered piece body 24 installed in the opposite direction is fixed by tightening a fixing bolt 26 inserted through the center thereof into a nut body 27 disposed on the core shaft 9 of the joint upper part 6 passing through the rotary plate 10. Further, this tapered piece body 24 is connected to the tightening shaft portion 24.
A bearing 28 is interposed between the outer tapered portion 24b and the outer tapered portion 24b, and the outer tapered portion 24b is movable as the rotary plate 10 rotates even if it is fixed to the joint upper portion 6. Reference numeral 29 denotes a socket into which the stump is inserted, and the socket 29 is integrated by screwing the tip of a mounting bolt 30 inserted through a screw hole 31 drilled in the socket pedestal 23 installed on the lower surface. Further, the angle-adjustable fixed cam 13 is fixed by tightening the end of the tightening shaft 32 that passes through the drum shaft 5 from the opposite side, and by screwing the end of the clamping shaft 32 into contact with the supporting piece 1a. A set screw 33 is provided. The fixed cam 13 allows the cam displacement to be changed in advance by setting the tightening position of the tightening shaft portion 32, so that the separation position (angle) of the locking pin 11 can be adjusted.

Next, to explain this effect, first of all, this knee joint 2
0, the lower leg pipe 2 is inserted into the connecting cylinder part 1b of the lower joint 1 and fixed with the tightening screw 34, and the socket pedestal 2 is attached to the upper surface of the upper joint 6.
Fix the thigh socket 29 to 3. In this state, the patient's stump is fitted into the socket 29 and set. In this case, alignment (axial position) adjustment is
Regulation bolts 2 inserted through all sides of socket pedestal 23
5 is suitably screwed in, and its tip is pressed against the tapered surface 24a of the tapered piece body 24, and the tapered piece body 24 is moved according to the degree of screw insertion, and the socket pedestal 23 is substantially moved.
Adjust the axial position of the knee joint by moving it left and right and forward and backward. At this time, the bowl-shaped ring 21 at the intermediate position can be shifted and inclined relative to the curved surface 23a of the socket base 23. Further, the exterior member A of the urethane cover is attached to the entire skeletal prosthesis.

Here, it is sufficient to perform a predetermined walk. That is, during the transition from the end of the kick-off phase, which is the end of the stance phase, to the swing phase, the knee joint is affected by the joint lower part 1, which is the ground contact side, as a reference.
The knee drum 4 is bent appropriately using the drum shaft 5 as a fulcrum (see FIG. 8). In this case, the knee drum 4, which tilts as it bends, pushes down the extension lever 16 connected to the support piece 15 at the rear end against the elasticity of the spring 18 attached to the support tube 17 on the lower side of the joint.
When the foot leaves the ground during the swing phase, the spring 18 pushes up the extension lever 16 and the knee drum 4 returns to its original position and rotates. That is, the release upon transition to the swing phase can be forcefully and quickly performed. Also, when you want to stop your knees at a predetermined bending position while walking, you can shift your weight to your thighs and use the lever section 6b on the lower surface of the upper joint 6 to tighten the clamping piece that forms the upper part of the slit of the knee drum 4. In order to press and turn the drum part 4c, the drum part 4a narrows and comes into tight contact with the drum shaft 5, performing a quick braking action and maintaining its bent state. In addition, in the knee flexion range associated with normal walking, the upper part of the joint 6
Even when the driven body 12 hanging down from the side slides on the cam surface 13a of the fixed cam 13, it does not reach the predetermined cam displacement position. Until it is pushed back, the rotary plate 10 is still immobile (fixed).

Next, when you want to swing your lower legs to the side when you sit with your legs crossed, etc., bend the upper part of the joint 6 using the drum shaft 5 as a fulcrum from a standing position, and the driven body 12 will move around the fixed cam 13 accordingly. When the cam surface 13a slides and reaches a predetermined angle (for example, 90°), the cam surface 13a reaches the maximum displacement position a, so the driven body 12 that slides on the cam surface 13a is pushed up, and The locking pin 11 on the rotating plate 10 side that is in contact with the rotating plate 10 is moved backward against the spring 11a and retracted into the rotating plate 10 (see FIG. 9).
is disengaged and becomes free. After this, the upper part of the joint 6
If the lower leg side is turned laterally, the lower leg side is swung to the side and the legs are crossed. This also applies to sitting cross-legged when you go up to the tatami room.

When returning to the original walking state, the lower leg side is rotated in the opposite direction to the above, and the locking pin 11 that has retreated into the rotating plate 10 is aligned with the axis of the driven body 12 of the joint upper part 6. After that, if you stand up with your lower leg side on the ground (straighten your knee joint), the driven body 12 will move to the maximum displacement a of the cam surface 13a of the fixed cam 13.
In order to move back from the position, the driven body 12 is pushed downward by the spring pressure of the upper locking pin 11, and the tip of the locking pin 11 touches the upper part of the joint 6.
The joint upper part 6 and the rotary plate 10 become one body by being inserted into the shaft hole 35 of the rotary plate 10 and engaging with the pin. After this, just walk normally as described above.

<Effects of the Invention> As described above, in the knee joint of the skeletal prosthesis of the present invention, the locking pin attached to the rotary plate disposed on the upper surface of the upper joint can be freely fitted to the driven body side mounted vertically on the upper joint. By making the driven body slide on a fixed cam at the end of the drum shaft of the knee drum provided at the bottom of the joint, a normal gait can be achieved when walking. In this case, an extension lever is provided on the knee drum to forcibly release the knee after it is flexed, allowing smooth and safe walking. Also, when you cross your legs while sitting or cross-legged, simply bend this knee joint to a greater degree than the maximum bending angle while walking, and the driven body on the upper side of the joint will follow the displacement of the fixed cam and move the locking pin upward. Then, the pin engagement between the upper part of the joint and the rotary plate is automatically released, allowing the lower leg to be swung sideways. When walking again, simply return the lower leg to its original position and rotate it to stand up, and the cam displacement restriction of the locking pin that becomes the click mechanism is released, and the cross-legged swinging mechanism is automatically locked, eliminating the hassle of walking. No operation required. In addition, in this case, depending on the setting of the tightening and fixing position of the fixed cam, sideways swinging is possible even when the knees are deeply bent or shallowly bent. Furthermore, the advantage of the present invention is that it has a cross-legged mechanism that eliminates the conventional push button, and the extension mechanism is built inside the skeleton instead of an externally mounted structure, so there is no reduction in the external members of the urethane cover, and it can be used for a long period of time. It has the advantage of being durable in use and easy to manufacture.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view, FIG. 2 is a front view, FIG. 3 is a side view seen from the opposite side, FIG. 4 is a longitudinal sectional side view of the main part, and FIG. Separated perspective view, Figure 6 is a side view of the state in use, Figure 7,
FIG. 8 is an explanatory diagram during normal walking, FIG. 9 is an explanatory diagram when the locking pin is separated, and FIG. 10 is an explanatory diagram when the robot is swinging sideways. DESCRIPTION OF SYMBOLS 1... Lower part of joint, 4... Knee drum, 5... Drum shaft, 6... Upper part of joint, 10... Rotating plate for cross-legged position, 11... Locking pin, 12... Follower, 13...
...Angle adjustable fixed cam, 13a...Cam surface, 16
...Extension lever, 18...Spring, 19...
Sliding piece.

Claims (1)

[Claims] 1 At the upper end of the lower part of the joint, a knee drum whose rear end is provided with an extension lever controlled by an elastic mechanism in the lower part of the joint is pivotally attached to the drum axis, and at the front of this knee drum there is a supporting arm of the upper part of the joint. and a rotary plate for cross-legged rotation is rotatably placed on the upper surface of the upper part of the joint, and the pin engagement between the rotary plate and the upper part of the joint is caused by an angle-adjustable fixed cam provided on the drum shaft. , a knee joint in a skeletal prosthesis that is characterized by being disengaged when the knee is bent over a predetermined angle.